new zealand



P.- M. McKAY. ARTIFICIAL ARM MID THE FITTINGS THEREFOIL.

APPLICATION FYI-ED MIG-EH19".

- Patented Jan. 23,1917.

UNITED STATES PATENT OFFICE.

PETER, MURRAY MQKAY, or ROCKVILLE, COLLINGWOOD, NEW ZEALAND, Assienon or ONE-HALF TO RICHARD WILLIAM BRICKELL, or MORNINGTON, NEW YZEALAND.

ARTIFICIAL A RM AND THE FITTINGS THEREFOR.

Specification of Letters Patent.

Patented, J an. 23, 1917.

Application filed August 21, 1916. Serial No. 116,027.

To all whom it may concern:

Be it known that 1, PETER MURRAY Mo- KAY, subject of the King of Great Britain, residing at Rockville, Collingwood, New Zealand, have invented new and useful Improvements in Artificial Arms and the Fittings Therefor; and I do hereby declare the following to be a full, clear, and exact description of the same.

This invention has been devised primarily with the object of providing an artificial arm of the type adapted to fit over a stump, that will be ofstrong construction so that it may be adapted for heavy working such as hammering digging and the like operations, and embodying special means whereby a rubber hand, tools of various kinds, such as a hammer head, grips for holding digging implements, carpentering tools and the'like, and other appliances may be readily fastened in the arm end and tightly gripped thereby.

The invention also consists insom'e special and novel forms of appliances for attachment to the arm by means of which different articles and tools may be held and operated by the use of the arm.

In fully describing the invention reference will be made tothe accompanying sheet of drawings, in which Figure l is a side elevation of the improved arm having a hammer attached thereto. Fig. 2 is a longitudinal section thereof, showing the stem or shank of the hammer withdrawn. Fig. 3 is an end view, on an enlarged scale,of the socket'end of th arm. Fig. 4 is a sectional elevation thereof, and Fig. 5 a back elevation thereof,.both being on the same scale. Figs. 6 and 7 are respectively plan and elevation of one of the improved gripping appliances for use with the arm shown. Figs. 8 and 9 are respectively similar views of an alternative form of such appliance.

The artificial arm is formed with the hollow socket a of the "usual shape adapted to fit over the stump of the wearers forearm,

and is in this invention preferably made of a light metal such as aluminum. It is attached in the ordinary way to the upper arm leather band I) by means of straps a, such band also having the usual neck strap connection 6. .As an additional means of attachment of the socket a to the band I), a length of webbing cl may be provided to ex: tend from the lower back edge" of the band through a loop cl on the lower back edge of the socket and then upward'to a strap d by which it is fastened to the band near its upper end. The provision of this extra connection'more effectively holds the socket in position on the arm stump and permitsof greater working strain being placed thereon.

To the outer end of the arm socket a is fixed a block of metal e of suitable shape that is firmly held in position by means of the straps 6 extending therefrom and preferably made integral therewith, one along the top and one along the bottom of the socket, as shown in Figs. 1 and 2 and fastened to the socket by riveting or otherwise. This block therefore forms a solid portion with the socket. The block is pierced centrally with a screw threaded recess and in such recess is screwed a plug or nut 9 having a central bore This bore extends right through the plug, its rear end being reduced in diameter so as to form a shoulder f while its internal surface is grooved longitudinally with a number of grooves h arranged at regular intervals apart around it and of even depth and width. Eight of these grooves are preferably employed. This plug may thus be removed when worn or damaged and a new one readily placed in position to replace it. If desired it may be held from movement by a pinch screw 9 Pivotecl to the back face of the block a is a short lever j that extends at its upper end out through a slot in such block and is formed at such end into a finger push y". This lever on its inside'is formed along one edge with a curved depression j (Fig. 5)

and a spring is normally keeps the lever drawn across so that the curve of such depression projects within one edge of the back end of the bore 7.

Each fitting or tool for attachment to the arm is formed with a shank or stem m havof it passing through the smaller end of the bore and is formed with a groove m at a suitable point therein to permit of the lever j fitting into the groove when the boss is pushed right in. The stem extremity is rounded, as shown at m so that when inserted it will push the lever j aside until it has been fully inserted, when the lever under the influence of its spring is will spring into the groove m and thereby hold the stem from withdrawal. Thus when the stem has been inserted into the bore it is locked firmly therein and is kept from any rotation by the engagement of its teeth with the grooves in the bore. The provision of the number of grooves and teeth shown in the drawings provides for the stem being inserted and held firmly at any desired angle. In this manner a solid jointing and locking of the tool stem to the arm is obtained so that in combination with the solid outer end of the arm, heavy work may be carried out by the manipulation of the arm, such for instance as hammering by means of a hammer 0 (Fig. 1) having a stem shaped as before described and attached to the arm in the manner mentioned. Other tools or devices such as a knife, a fork, a screw driver or a rubber hand may besimilarly locked to the arm. To release the fittings it is only necessary to push the lever back by pressure on the push 7'" when the stem will be released from the lever and may be drawn out.

'The fitting shown in Figs. 6 and '7 is designed to allow of the handle of a shovel, hay fork, or other like appliance being firmly gripped and then worked by the artificial arm. It consists in a pair of jaws 72- 0 pivoted together at r and claw shaped to fit between one another as shown, and provided with handle extensions ss beyond their pivot and with a strong spring 8 extending between their handles and keeping the jaws normally closed. The stem or shank m of this fitting is arranged to extend at an angle to the plane of the jaws so that when inserted in the arm, and a tool or implement handle is inserted between and gripped by the jaws, such handle will extend in relation to the arm at the proper angle for the working of the tool. The angle may be varied at will by the provision made and already described, for the insertion and lock- 111g of the stem within the arm socket. The

gripping faces of the jaws ;0p may be scored or serrated, as shown, to aid their gripping action upon the tool or implement handle.

The alternative form of fitting shown in Figs. 8 and 9 is designed to afford a grip for the operation of such tools as are required to be held in a line continuously with the plane of the fore-arm for their operation, as for instance to hold and work the crank of a boring brace or the handle of a saw. In this form the stem m forms one of the handles of the jaws pp' and is disposed continuously therewith, the grip being opened and closed by pressure upon and release of the other handle. If desired, the toothed boss n may be made to revolve loosely on the stem so that in working a tool at angles, the jaws may be able to accommodate themselves to the varying angles assumed. In such a case the boss will be held between collars t fixed to the stem.

I claim 1. An artificial arm characterized by having its end formed with a metal block and provided with a plug screwed into a threaded aperture therein, such plug being formed with a central bore extending through it having grooves formed longitudinally along its internal peripheral surface to receive correspondingly toothed stems of fittings for the arm, substantially as specified.

2. An artificial arm characterized by having its end formed with a metal block and provided with a plug screwed into a threaded aperture therein such plug being formed with a central bore extending through it having grooves formed longitudinally along its internal peripheral surface, a stop at the inner end of the bore and a spring catch situated on the inside of the block and normally overlying one side of the bore, in combination with a stem having a boss adapted to fit into the bore and formed with teeth fitting the grooves therein and an extension beyond the boss adapted to project through the bore and formed with a groove around it adapted to be engaged by the said spring catch, substantially as specified.

3. A fitting for an artificial arm of the class herein referred to consisting in a pair of curved jaws pivoted together and provided with handles extending beyond their pivot and with a spring situated between such handles and normally keeping the jaws closed, and a stem or shank adapted to be inserted and locked within the arm, extending at an angle to the plane of the jaws, substantially as specified.

4. A fitting for an artificial arm of the class herein referred to, consisting in a pair of curved jaws pivoted together and having a stem' or shank adapted to be inserted into and locked within the arm extending beyond the pivot continuously with one of the jaws, specification in the presence of two subscriba handle extending beyond the pivot fro n ing witnesses. the other jaw and a spring situated between such stem or shank and handle, normally PETER MURRAY MCKAY' 5 keeping the jaws closed, substantially as Witnesses:

specified. W. ALEXANDER, In testimony whereof, I have signed this M. E. BROWN.

Bopien of this patent may be obtained for five cents each, by addressing the Commissioner of Patentn.

Washington, D. G." 

